Howto Convert 0.4082482905 To 1/sqrt(6) ?

[bvidinli Profile]

As you know, 1/sqrt(6) = 0.4082482905

How can I convert 0.4082482905 back to 1/sqrt(6) ? (assuming I do not know 1/sqrt(6))
using casio calculators, fx 9850 or similar ? (using either a program, addin or similar.)

Because, sometime, I find these numbers as result of calculations, however, these should be shortened...

or, similarly, 1/sqrt(3)

[helder7]

Convert 0.4082482905 back to 1/sqrt(6) (currently) is impossible.

During calculations, you can work with the exact value using the key [F<->D].

EDITED:
Casio Calculators give an approximate value:
1/sqrt(6)=0.4082482905

The (more) exact value (approximate) should be:
1/sqrt(6)≈0.40824829046386

So it is normal that the calculator does not recognize this value as a fraction. Maybe calculator only accept 10 decimal digits.

The site wolframalpha can discover the original value: http://www.wolframalpha.com/input/?i=0.4082482905

[hayzel Profile Website]

it is not impossible and many algorithms exist for this.
But all are approximations.
you can see for example the RIES algorithm:
http://mrob.com/pub/ries/index-2.html#algorithm
So to make this on calculator, you have to write an analogous code to the calculator as an addin.

[Arkhs Profile]

Calculator only supports 10 decimals:
0.9999999999 = 0.9999999999
0.99999999999 = 1

[flyingfisch Profile]

Arkhs is correct, only 10 digits are supported by the calculator. This is stated in the manual.